Motion-picture projecting machine



April 12 1927.

v A. s. HOWELL MOTION PICTURE PROJECTiNG MACHINE 4 Sheets-Sheet 1 Filed Auz. 16. 1924 April 12, 1927..

A s. HOWELL MOTION PICTURE PROJECTING MACH INE Filed Aug. 16. 1924 4 Sheets-Sheet 2 ill/ 4 1 Ill 2 April 12, 1927. 1,624,732-

- A. s. HOW ELL MOTION PICTURE PROJECTING MACHINE Filed. Auz.-l6, 1924, 4 She ets-Sheet 3 VMQ M April 12 1927. 1,624,732

A. s. HOWELL 4 MOTION PICTURE PROJECTING MACHINE Filed Auz. l6. 1924 4 Sheets-Sheet 4 ZZZ/6'71! dim r/d 1/01/4 11 Patented Apr. 12, 1927.

1 UNITED STATES PATENT- orrlca.

ALBERT S. HOWELL. OF CHICAGO, ILLINOIS, ASSIGNOR TO THE BELL 8c HOWELL. COM- PANY, or CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

MOTION-PICTURE PROJECTING MACHINE.

Application filed August 16,1924. Serial No. 732,469.

One of the features of the invention relate .to the provision of means for effecting unattended operation of a motion picture projecting machine for long periods of time without the use of an endless film and its attendant disadvantages. The invention contemplates reversing the direction of feed of the film at opposite ends of a predetermined travel of the same, as fed by the feeding mechanism of the. projecting machine, whereby the film is reeled off of and onto the usual film reels employed on projectingmachines. V Other features of the invention relate to means for interrupting the projecting light on the film during stoppage or reversal of the film whereby to prevent damage to the film by reason of the projecting light playing too '.long on one portion of the film, thus permitting a very'intense projecting light being used without danger of in ury to the film.

With these features in view my inven tion. consists in certainfeatures of novelty in the construction, combination, and arrangement of parts by which the said features and certain other features, hereinafter appearing, are effected, all as fully described with reference to the accompanying draw ings and more particularly pointed out in the claims.

In the said drawings-- Figure 1 is a topplan view of a motion picture projecting machine with parts, broken v- I Figures 2 and. 3 are enlarged sectional views on the line 2-2 of Fig. 1 with a part broken away. i I Figure 4 is a partial sectlon on the line 4-4 of Fig. 3.

Figure 5 is a partial section on the line 5-5 of Fig. 2.

Figure 6 is uninterior view on the line 66 of Fig. 1 with parts removed.-

Figure 7 "is an interior view on the line 7-7 of Fig. 1 partially in section and par.- tially broken away. f

Figure 8 is a partial section on the line 8-8 of Fig. 9.1 7

Figure 9 is an enlarged partial section on the line 99 of Fig. 7.

Figure 10 is a partial side elevation of the projecting machine with parts broken awayand in section.

Figure 11 is an enlarged partial section on the line 111.1 of Fig. 7.

Like characters of reference indicate like parts in the several views.

Referring to the drawings the feeding mechanism of the projecting machine embodies an intermittent film feeding mechanism for intermittently moving the film through an apertured film guide 1 and con stant feed sprockets 2 operating in correspondence with the intermittent feeding mechanism for feeding the film between the guide 1 and respective of film reels mounted on spindles 3 of the machine, all as is usual.

a lamp within a lamp chamber 4 to the See Fig. 1. Projecting light from rear of the feed guide projects lightupon the film at the aperture of the guide 1 and the image on the film isprojected thereby through a lens 5 in front of the aperture of the guide, a shutter, operated with the feeding mechanism, periodically interrupting the projecting light during intermittent movement of the film in the guide, all as is usual.

An electric motor 6 is assembled in the frame of the projecting machine, and is disposed to one side of the lamp chamber 4 on a horizontal forwardly and rearwardly extending axis. The shaft 7 of the motor extends forwardly from the motor,'and secured on this shaft adjacent its front end is an air impeller wheel 8 which is disposed in an air chamber 9 formed in the frame of the machine and extending transverselv between the guide 1 and the lamp chamber 4. This air chamber communicates with the aperture of the guide through a When in operation the impeller wheel draws air through openings 12 in the p'ortion'of the frame of the machine forming the motor housing and then through'a large aperture 13 in the wall of the frame between the air chamber and the motor housing of the frame.

The motor 6 drives the film feeding mechportion anism and shutter through the medium of a releasable'friction clutch in the following manner. See Fig. 10. A spur driving pinion 14 is rotatably'mounted on the motor shaft 7 in front of the hub of the impeller wheel 8 and meshes with suitable gearing forward washer 15. A circular coiled tension spring 18 encircles the shaft 7 and engages outwardly facing concave surfaces of the wedge members 17 for yieldably urging thewedge members inwardly to engage the forward washer 15 and to press the washers 15 and the inion 14 therebetween against the hub of t e impeller wheel 8 whereby to frictionally drive the pinion from the motor shaft for driving the feeding mechanism and shutter from the motor. A stud member 19 is mounted for longitudinal movement in a concentric bore 21 in the forward end of the motor shaft, and is provided with an intermediate reduced portion 22. Portions of the wedge members 17 project into the bore 21 for cooperation with the stud 19 to release and engage the clutch with longitudinal movement of the stud. Thus, when the stud is positioned, as shown in Fig. 10, so that the reduced portion'22 of the stud permits inward movement of thewedge members under the influence of the spring 18, the clutch is engaged as before described. When the stud is moved to a rearward position the large portion of the stud moves the wedge members 17 outwardly against the influence of the spring 18 and releases the washers l5 and pinion 14 against the hub of the impeller'wheel 8, a shallow circumferential groove 23 on the stud immediately in front of the reduced portion 22 thereof being engaged by the wedge members 17 under the influence of the spring 18 to 'releasably maintain the clutch disengaged.

A clutch lever 24 is pivoted at'25 on a horizontal axis and has an arm provided with a roller 26 which is engaged in a circumferential groove 27 on the forward end of the stud 19 for shiftin the stud longitudinally to engage am? disengage the clutch as heretofore described. The main portion of the lever 24 is disposed exteriorly of the frame of the'machine for manual operation and sweeps in front of a wall thereof, stops 28 on the frame limiting movement of the lever in both directions.

The reel spindles 3 are alternately driven with the film feeding mechanism to take up the fed film depending upon the direction of operation of the film feeding mechanism as is usual by a belt and pulley mechanism 29. See Fig. '1. v

A motion picture projectin g machine of the character described herein is described and. claimed in my co-pending application, Serial No. 572,170, filed July 1, 1922, for motion picture projecting machine and the like, and needs no further description for the present purposes.

The motor 6 is of a usual type, and the rear end of the housing thereof is formed by a removable end cap-31 which carries the,

motor brushes 32, see Fig. 6, which engage the commutator 33 at the rear end of the armature of the motor. Mounted on the inside of the end cap 31 for pivotal movement on the axis of the motor shaft is a switch member 34 of insulating material, and mounted on this member are a pair of metal contacts '35 which alternately contact opposite brushes 32 in opposite positions of the member 34. The contacts are provided with spring clips 36 in which the 'motor circuit wires are secured. Thu is. formed a reversing switch and the arrangement is such that when the member 34 is at one end of its movement the motor operates in one direction and when the member 34 is at the other end of its movement the motor operates in the opposite direction. A stud 37 secured .on the member 34 extends rearwardly there from through. an opening in the cap 31 so that the member 34 may be operated from the outside of the motor housing, the opening serving to limit movement of the mem ber 34 at both ends of its movement. A plurality of radially disposed compression spring devices 38 are disposed between the end cap' 31 and the switch'member 34 and serve to yieldably maintain the member 34 :at either end of its movement by reason of clutch by'suspending the compression of the their axes passingon'both sides of the pivotal axis of the member 34 in its movement in an obvious manner.

Referring to Figs; 1, and 2-5 inclusive, 2. second cap member 39 is secured on the rear end of the end cap 31 and'forms an enclosure therewith. Pivotally mounted on an axis coincident with the pivotal axis of the switch member 34,'by means of a stud 41 secured on the transverse wall of the cap member 39, is a bell crank lever 42, one of the arms of which is provided witha slot embracing the stud 37 so that the reversing switch may be operated by the lever in both directions. ,The main portion of this bell crank lever together with the other arm thereof is bifurcated in a plane normal to the pivotal axis of the lever, and disposed in the space provided-by 'thebifurcated portion of the lever and journaled on the stud 41 is a stop gear 43. A second stop gear 44 is. disposed in the s ace provided by the bifurcated portion of tie lever and is'journaled on a stud 45 which is removably secured on the other arm of the lever by means of a headed screw 46. The stop gears 43 and 44 mesh and coo rate with each other as hereinafter described and are preferably constructed for cooperation as follows. The teeth of these gears are formed similar to ordinary spur gear teeth except as follows.

The teeth of the gear 43 are normal, except that one flute 47 thereof is relatively shallow, and one tooth 48 of the gear 44 is a normal tooth whereas the remainder of the teeth of this gear are relatively short, they being cut of! substantially at the pitch line of the gear. The gears 43 and '44 have different numbers of teeth, as shown the gear 43 having 52 teeth and the gear 44 having 53 the gear 43 until by reason of the progressive teeth, and cooperate in the following man: ner. In the rotation of the gears 43 and 44 the short teeth of the gear 44 clear the ,shallow flute 47 and the long tooth 48 of the gear 44 engages in the normal flutes of tooth engagement caused by the difference in the number of teeth in the gears thelong tooth 48 engages in the shallow flute 47 and interrupts rotation of the gears in the di'- rection ofirotation, as shown in Figs. 2 and .3. This action takes place in the rotation of the gears in both directions" as is obvious, and is utilized as hereinafter described.

Rotatably mounted on a stud 49 secured on the transverse wall of the ca member 39 is a spur pinion 51 and carrie on a hub of the pinion is a large bore-d spur gear 52 which is connected withthe pinion to drive the same by a ieldable friction clutch consisting of a pair of friction washers 53 disposed onopposite sides of the gear and engaging the web thereof, a compression spring 54, and a nut 55 screwthreaded on the outer end 'of the hub of the pinion 51 and compressing the spring 54, washers 53 and the web of the gear 52 against the main portion of the pinion. See Figs. 2, 3, and 4. A spur driving pinion 56 is secured on the rear end of the shaft 7 of the motor and meshes with the gear 52 for driving the same from the motor. v

Another stud 57 is secured on the transverse wall of the cap member 39, and a gear unit consistingof a pinion 58 and a large spur gear .59 secured therewith is rotatablly mounted thereon. The gear 59 meshes wit the pinion 51, and the pinion 58 meshes with .the stop gear 43, thus completing a reduction gear train for driving the stop gear 43 from the motor. The teeth of the pinion 58 are relatively short.'they being cut off substantially at the pitch line thereof, to clear the shallow flute 47 of the gear 43.

- In the operation of the motor the stop gear 43 is driven through the 'reduction gearing, and the stop gear 44 rotates with the gear 43 until the long tooth48 engages the shallow flute 47. When this engagement is made rotation of the stop gears 43 and 44 is suspended, whereupon the lever 42 is moved with the gear 43 to operate the reversing. switch to reverse the motor. Fig. 2 shows the position of the parts just as the long tooth 48 and the shallow flute 47 engage,

and Fig. 3 shows the position of the parts after the bell crank lever has been moved to the opposite end of its movement. Upon reverFal'of the motor the stop gears 43 and 44 rotate on each other in the opposite direction until the long tooth 48 again engages the shallow flute 47 whereupon the lever 42 is again actuated to operate the reversing switch to reverse the motor. The yieldable friction clutch between the pinion 51 and gear 52 compensates for the momentum of the motor and film feeding mechanism during reversal to prevent undue strain on the partsof-t-he mechanism.

Thus the motor is automatically reversed at substantially equal intervalsv in the operation thereof, and when the clutch for driving'the film feeding mechanism from the motor is. engaged the film feeding mechanism is automatically reversed at opposite ends of a predetermined travel of a film fedby the feeding mechanism.

Thus it will be observed that the machine to effect such operation an endless film is not employed with attendant disadvantages.

a The period of operation of the motor betweenfi'eversals may be shortened by substituting for the stop gear 44 anotherstop gear having the'same pitch and number of. teeth with more than one long tooth for cooperation with the shallow flute 47 of the stop gear 43, and it is for this reason that the stud 45 upon which the gear 44 is mounted is removably mounted on the bell crank lever 42 as hereinabove described.

The stud 37 extendsoutwardly through suitable opening in the cap 39 for manual operation of the reversing switch. See Fig. 1. w

tively great intensity may be used without In order that a projecting light of-relano i danger of injury to the film during reversal ill with a vertically disposed cylinder form-ation 61 of rectangular cross section di sed above the aperture 11 and havin its ower end open and communicating with the air chamber. See Figs. 7, 8, and 9. Secured in the air chamber at one side of the aperture 11 is avertically disposed slotted guide 62. A shutter 63 disposed in a vertical transverse plane is provided with a lateral extension 64 at its lower and formed to interlock with the slotted guide 62 for guiding the lower end of the shutter for vertical movement. Secured to the upper end of the shutter is a horizontally disposed rectangular piston 65 which is engaged in the cylinder formation 61 for vertical movement therein and cooperates with the slotted guide 62 and extension 64 for guiding the shutter for vertical movement. The shutter 63 and the piston 65 attached thereto are, under the influence of gravity, urged to the lower end of their movement and when in this position the shutter is closed and lies in back of the aperture 11 and prevents the projecting light from passing therethrough onto the film in the aperture of the guide 1, as shown in Figs. 7 and 9. When the shutter and piston are at the upper end of their movement, as shown in dotted lines in Fig. 7, the shutter is open and is disposed above the aperture llto permit the projecting light to pass through the aperture 11 onto the film.

he upper end of the cylinder formation above the piston is closed and communicates with the atmosphere by means of an air passage 66 and an exposed port-67on the wall of the frame over which the aforementioned clutch lever 24 sweeps for purposes hereinafter described.

Rotation of the impeller wheel 8 by the motor in either direction creates air pressure in the air'chamber and acts on the lower side of the piston to move the same, together with the shutter, upwardly whereby to open the shutter, the passage 66 and port 67 preventinga counter pressure being developed above the piston. When the motor is stopped or reversed the ressure in the air chamber 9 drops and t e piston and shutter move downwardly under the influen-e of gravity into closed position until the air pressure in the air chamber is suflicient to again lift the piston and shutter. Thus the shutter is automatically operated to interrupt the projecting light during stoppa e or reversal of the motor and to permit t e projecting light to function during normal operation of the motor, and when the film feeding mechanism is being driven by the motor through the en agement of the hereinbefore mentioned clutch for driving the feeding mechanism from the motor the shutter is automatically operated to interrupt the projecting light on the .filmduring stoppage or reversal of the feeding mechanism and to permitthe projecting light to function during normal operation of the feeding mechanism.

The hereinbefore mentioned clutch lever 24 in its movement to engage and disengage the clutch for driving the film feeding mechanism from the motor sweeps over the port 67 and forms a valve therewith. The port67 is so arranged that when the clutch lever is in clutch engaging position, as shown in Figs. 1 and 10, the port 67 is open and fllllitlODS as hereinbefore described. When, however, the clutch lever is in clutch disengaged position, as artially shown by dot and dash lines in ig. 10, it overlies the port 67 and closes the same. This closing of the port 67 permits equal pressure being developed above andbelow the piston 65, the air passing upwardly between the piston and cylinder formation, whereupon the shutter 63 and piston 65 move downwardly into closed position while the motor and air impeller are operating and the film feedin mechanism is stopped by reason of the drlving clutch being disengaged.

In order that the. shutter ma he opened when the motor is operating an the feeding mechanism is stopped by reason of the disengagement of the driving clutch, a valve 68 is rovided which communicates with the "cylin er formation 61 above the piston 65, and is spring pressed into closed position and may be manually opened to lower the pressure above the piston to open the shutter.

While I have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my invention,

but-

claim as new and desire to secureby Letters Patent the following: g

. 1; .In a motion picture rojecting machine the combination with a riven film feeding mechanism, of means for reversing the di- Having thus described my invention I I H rection of operation of the feeding mechanism, a pivoted member for operating said reversing means, a revoluble stop gear dis- ,posed coaxial with the pivoted member, a

second revoluble stop gear carried by the pivoted member and meshing with the first mentioned stop gear and cooperating therewith, and means for driving said first mentioned stop gear with the film feeding mechanism whereby to operate said pivoted member to operate said reversing means to effect reversal of the direction of operation of the feeding mechanism at opposite ends -of a predetermined travel of a film fed by said feeding mechanism.

, 2. In a motion picture rojecting machine the combination with a riven film feeding mechanism, of means for reversing the di- 1 different numbers of teetlf'and one having a tioned stop gear with the film feeding flute thereof relatively shallow and the other havin teeth thereof relativel short to clear said shallow flute in the rotation of the gears .and having a long tooth cooperating with said shallow flute to interrupt rotation, of

the gears whereby to effect movement of the pivoted member to operate said reversing means, and means for driving said firstmenmechanism.

3. In a motion picture rojecting machine the combination with a riven film feeding mechanism, of meansfor reversing the direction ofoperation of the feeding mechanism, a pivoted member for operating said reversing means, a revoluble stop gear disposed coaxial with the pivoted member, a second revoluble stop gear carried by the pivoted member and meshing with the first mentioned sto gear, said stop gears having different num ers of teeth and one having a flute thereof relatively shallow and the other having teeth thereof relatively short to clear said shallow flute in the rotation of the gears and having a long tooth cooperating with said shallow flute to interrupt rotation of the gears whereby to effect move ment of the pivoted member to operate said flute ;to interrupt rotation of the gears reversing means, and means for driving said first mentioned stop gear with the film feeding mechanism including reduction gearing and a 'yieldable friction clutch adapted to compensate for momentum during reversal of t e film feeding mechanism and said reduction gearing including a pinion meshing with said first mentioned stop gear and hav-' ing relatively short teeth to clear said shallowflute.

4 4. In a motion picture projecting machine the combination with an electric motor for operating the same in either. direction, of switch means for reversing the motor, a p-ivoted member for operating the switch means, a revoluble stop gear disposed coaxial with the pivoted member, a second revoluble stop gear carried by the pivoted member and meshing with t e first mentioned sto gear, saidstopgears having different num ers of teeth and one havin a flute thereof relativelyshallow and t e other having teeth thereof relatively short to clear said shallow flute in the rotation of the gears and having a. long tooth cooperating with said shallow whereby toefli'ect movement of-the'pivoted. member to operate said switch meansto reverse the motor, and means for 'drlvu'ig 'tioncd stop gear and teeth to clear said shallow flute.

said first mentioned stop gear from the motor including reduction gearing and a yielclable friction clutch adapted to com pensate for. momentum duringlreversal, of

the motor and said reduction gearing includimg a plnion 1116811111" wlth said first menhaving relatively short 5'. In a motion picture projecting machine the combination with a driven film feedin mechanism, of a shutter movable into an out of position to interrupt the projecting light on a film fed by said feeding mecha- -nism,'an air impelling device driven with the feeding mechanism, means for automatically reversing the direction of operation of said feeding mechanism and said" impelling device at oppositeends of a predetermined travel of a film fed by said feeding mechanism, and pneumatic means responsive to air affected by the operation of said impelling means for causing the shutter to be closed during reversal of the feeding means and to be open during operation of the feeding means between reversals thereof.

6. In a motion picture projecting machine the combination with a driven film feeding mechanism, of a shutter movable into and out of position to interrupt the projecting light on a film fed by sald feeding mechanism and yieldably urged into closed posi-' tion, an air blower driven with the feeding mechanism, means for automatically reversing the direction of o eration of vsaid feed:

in mechanism and air blower at opposite ends of a predetermined travel, of a film fed by said-feeding mechanism, and pneumatic means res onslve to air affected by the operatiqn 0 said blower for operating said shutterinto open position and maintaining it in open position during operation of the feeding mechanism and blower between re versals and permitting the shutter. to close during reversals of the feedingv ;I n'echanism and blower. I

7-. In a motion picture projecting-machine the combination with a film feeding mechanism and an electric motor for driving the same in both directions, of a switch for reversing the motor, means driven by the mo tor for automatically operating said switch to reverse the motor at predetermined substantially equal intervals in the operation thereof, a shutter movable into and out of position to interrupt the projecting light on a film fed by said feeding means, an air impeller driven by the motor in both directions, andpneumatic means responsive to air affected bysaid impeller for effecting closure of. the shutter during reversal? of the and an electric motor for driving the same motor and opening of the shutter during in both directions, of a switch for reversing the motor, means driven by the motor for automatically operating said switch to reverse the motor at predetermined substantially equal intervals in the operation thereof, a shutter movable into and out of position to interrupt the projecting light on a film fed by said feeding means and yieldably urged into closed position, an air blower driven by the motor in both directions, and pneumatic means responsive to air affected by 0 eration of said air blower for moving sait shutter into and maintaining it in open position during normal operationof the motor.

9. In a motion picture projecting machine the combination with a film feeding mechmism, an electric motor and a releasable clutch for driving the feeding mechanism from the motor in both directions, of switch means for reversing the inotor, means operated by the motor for automatically operating said switch means to reverse the motor,

at predetermined substantially equal intervals in the operation of the motor, means for interrupting the projecting light on a film fed by said feeding means and adapted to be rendered non-elfective, means for automatlcally causing said interrupting means 1 to interrupt the projecting light during stoppage or reversal of the motorand to be non-eifective during normal operation of the motor, and means for causing said interrupting means to interrupt the projecting lightwvhile said clutch is released and permitting control of the interrupting means by said means for automatically controlling the interrupting means when the clutch is engaged.

10. In a motion picture pro'ecting ma-' chine the combination with a lm feeding mechanism, an electric motor and a manual-' ly controlled releasable clutch for driving the feeding mechanism from the-motor, of .1 switch for reversing the motor, means operated by'the .motor for automatically operating said switch to reverse the motor at predetermined substantially equal intervals -m the operation of .the motor, a shutter movable into and out of position to interrupt the projecting light on a film fed by said feeding mechanism, an air im ller driven by the motor independently 0 said clutch, pneumatic means responsive to air affected by the operation .of said impeller for causing said shutter to be closed during stoppage and reversal of the impeller and motor and to be open during normal operation of the impeller and motor, and means I for causing said shutter to be'closed during release of said clutch and permitting control of the shutter by said impeller when the clutch is engaged.

11. In a motlon picture pro'ecting machlne the combination with a film feeding by said air blower for causing said shutter to open and remain open during normal operation of the blower and motor and permitting the shutter to close during stoppage or reversal of the motor and blower and an air valve controlled with said clutch for rendering said pneumatic means unresponsive to air affected by the operation of the blower during release-of the clutch and permitting response while the clutch is engaged. k U

12. 'In a motion picture pro ecting machine the,combination with a in feeding mechanism and a releasable clutch for driving the feeding mechanism, of means for interrupting the projecting lightupon a, film fed by said feeding mechanism and adapted to be rendered non-effective, and means whereby sald interrupting means 1s controlled with the clutch to interrupt the projecting light when the clutch is released (and to permit cooperation of the rojecting 1i ht with the film when the clutc is engage 13. In a -motion picture pro'ecting machine the combination with a 1m feeding mechanism, a driving means and a releasable clutch for driving the feeding mecha-,

nism from the driving means, of a shutter movable into and outof position for interrupting the projecting light on a film fed by said feeding mechanism, air impel ing means driven by said driving means independently of said clutch, pneumatic means responsive to air aflected b operation of sald mpellmg means for e ecting opening of the shutter during operation of said air impelling means and closing thereof during non-operation of said air impelling means,

and means whereby the shutter 'is. caused to close with release of the clutch and permitted to open when the clutch is engaged.

chine the combination with a feeding mechanism, an electric motor and a releasable clutch. for driving the feeding mechanism from themotor, of a shutter movable into and out of position for interrupting the projecting light on a film fed by said feeding mechanism and yieldably urged into closed 'tion, air impelling means permanerit y connected with the motor to be 0. 14. In a motion picture pro'ecting madriven thereby, pneumatic means iisponsive an air valve for rendering said pneumatic to air affected by operation of said impelmeans unresponsive to air affected by opera-' ling means for operating the shutter into and tion of said impellingmeans.

maintainingvthe same 1n open position, and In witness whereof I hereunto aflix my 5 means whereby the shutter is caused to close signature this 13th day of August, 1924.

with release of the clutch and permitted to open when the clutch is engaged including ALBERTS. HOWELL. 

